I was reading about the [Hasse-Weil bound](https://terrytao.wordpress.com/2014/05/02/the-bombieri-stepanov-proof-of-the-hasse-weil-bound/) for the number of points in on a curve over the finite field $\mathbb{F}_q$.  

$$ \big| |C(\mathbb{F}_q)| - (q+1) \big| \leq 2g \sqrt{q} $$

However, this reminded me quite a bit of the [Chebyshev inequality](https://en.wikipedia.org/wiki/Chebyshev%27s_inequality).

$$ \mathbb{P}\big[ |X - \mathbb{E}[X]| \geq k \sigma \big] \leq \frac{1}{k^2} $$

Is there a way to prove - or at least interpret - the Hasse-Weil bound as an estimate of the "Expected" number of points on a curve?

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Maybe if we do the correspondence $X \mapsto |C(\mathbb{F}_q))| $ , so the random variable is the number of points of the curve.

Then $k \mapsto g$ so the genus can be read as the number of "standard deviations" away from the norm.

We can even justify $\mathbb{E}[X] \mapsto q+1$  since a generic projective curve $f(x,y,z) = 0$ should have one solution for every $x \in \mathbb{F}_qP^1$ which has $q+1$ elements.


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Even more far-fetched is to declare the probability measure $\mu \mapsto \chi$ the Euler characteristic of the curve.   This is suggested since apparently the [Lefschetz trace formula](https://en.wikipedia.org/wiki/Lefschetz_fixed-point_theorem) plays a role.

$$ |C(\mathbb{F}_{p^n})| = \big( p^n + 1 \big)- \sum_{i=1}^{2g} a_i^n $$

So the "variants" amounts to controlling the numbers, $|a_i| \leq \sqrt{p}$.  At this point the details are beyond me anyway.